1. Field of the Invention
The present invention relates to a strain relief boot for a connector. The invention more particularly concerns a strain relief boot which is adjustable and where the adjustable strain relief boot is used in combination with an optical connector having an optical fiber.
2. Discussion of the Background
The application of fiber optics to the telecommunication and data storage industries is expanding ever day. Fiber optics enables the high-speed transmission of communications and data. Connectors for optical fibers can be found in the back of instrumentation, telecommunication, routing, and switching cabinets. These cabinets accept a large number of fiber optic connectors. The optical fibers project away from the connector and tend to bend toward the ground due to the effect of gravity or the optical fibers are bent in a different direction due to an externally applied force. An optical signal passing through an optical fiber can experience a power loss if the bend radius of the optical fiber is too great. In order to prevent the optical fiber from being bent beyond a minimum bend radius, strain relief boots can be attached to the optical fiber in a region adjacent to the connector. The strain relief boot provides for a gentle, smooth, non-abrupt transition of the optical fiber from the connector to some other environment so as to maintain the optical signal at an acceptable power level.
Typically, strain relief boots have a straight, unbent shape when they are not subject to an externally applied force. Such a strain relief boot is disclosed in U.S. Pat. No. 5,781,681 which is hereby incorporated herein by reference. Other strain relief boots having variable shapes are also known and are disclosed in U.S. Pat. Nos. 5,933,557; 5,764,839; 6,039,081; and 5,889,910 all of which are hereby incorporated herein by reference. Yet other strain relief boots have a nominal shape of ninety degrees between the connector and the rest of the optical fiber. Such geometry is disclosed in U.S. Pat. Nos. 5,347,603; 5,640,476; 5,710,851; 6,134,370; and 5,037,175 all of which are hereby incorporated herein by reference. FIG. 12 is taken from U.S. Pat. No. 5,781,681 showing a prior art connector 40. The prior art connector 40 includes the prior art optical fiber 47 which is surrounded, adjacent to the connector, by the prior art strain relief boot 45. FIG. 13 is a cross sectional view of the prior art connector 40 of FIG. 12 showing how the prior art strain relief boot 45 bends when the prior art optical fiber 47 is subjected to a side load.
Due to the shear number of optical fibers populating the above-mentioned cabinets, the optical fibers and their associated strain relief boots bend at the same angle thus resulting in the optical fibers contacting each other and entangling with each other.
Thus, there is a need to provide for the projection of an optical fiber away from its connector at an angle which is different than the projection of another optical fiber away from its associated connector so as to avoid entanglement and congestion of the massive number of optical fibers.
It is an object of the invention to provide a strain relief boot which maintains a predetermined, fixed angle but is also adjustable so as to maintain at least another, predetermined, fixed angle.
It is a further object of the invention to provide a strain relief boot that prevents the minimum bend radius of the optical fiber from being exceeded.
It is another object of the invention to provide a strain relief boot that prevents adjacent optical fibers from becoming entangled.
In one form of the invention the adjustable strain relief boot includes a stationary portion and a moving portion slidably connected to the stationary portion. The stationary portion is adapted to be attached to the connector of the optical fiber. The moving portion is associated with the optical fiber so as to guide the optical fiber. The moving portion is adjustable between at least two fixed, predetermined positions relative to the stationary portion.
Thus, the invention achieves the objectives set forth above. The invention provides a strain relief boot which projects the optical fiber away from its connector at a fixed, predetermined angle and where the strain relief boot can be adjusted to another fixed, predetermined angle.